Investigation of the Effects of Diesel Injection Strategies in a Reactivity Controlled Diesel iso-Butanol Compression Ignition Engine

Due to very low PM and NOx emissions and considerable engine efficiency, dual-fuel combustion mode such as RCCI strategy attracted lots of attention compared to other combustion modes. In this numerical research work, the impacts of direct injection timing and pressure of diesel fuel on performance and level of engine-out emissions in a diesel-butanol RCCI engine was investigated. To simulate the combustion process, a reduced chemical kinetic mechanism, which consists of 349 reactions 76 species was used. The influence of thirty-six various strategies based on two diesel spraying characteristics such as injection pressure (650, 800, 1000, and 1200 bar) and diesel spray timing (300 to 340 CA with 5 CA steps) have been examined. Results indicated that, under the specific operating conditions like 1000-bar spray pressure by direct injection at 45 CA BTDC and the spray angle of 145 degrees, the level of cylinder-out pollutants such as CO (up to 26%), NOx (about 86%), PM (by nearly 71%) and HC (about 17.25%) have been simultaneously reduced. Also, ISFC decreased by about 2.3%, IP increased by about 2.4%, and also ITE improved by nearly 2% compared to the baseline engine operating conditions.